Part I Introduction. The law, practice and this book. Professional and ethical issues. Part II Legal principles. Capacity to vote. What are the legal principles?. Part III Legal tests of capacity. Capacity to deal with financial affairs. Capacity to make a will. Capacity to make a gift. Capacity to litigate. Capacity to enter into a contract. Capacity and personal relationships. Capacity to consent: the criminal law and sexual offences. Capacity to consent to and refuse medical treatment. Capacity to consent to research and innovative treatment. Part IV Practical aspects of the assessment of capacity. Practical guidelines for doctors. Practical guidelines for lawyers. Appendix A Case studies. Appendix B The Official Solicitor. Appendix C Practice Note (Official Solicitor: Declaratory Proceedings: Medical and Welfare . .). Appendix D Practice Note (Official Solicitor: Appointment in Family Proceedings). Appendix E Medical certificate for the Official Solicitor with Guidance Notes. Appendix F Medical certificate for the Court of Protection with notes for guidance. Appendix G Sample letter: Test of Capacity